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Cetaceans were surveyed using ship transects across the seas of Raja Ampat (West Papua) in November and December 2007. Sighting effort reached 120 hours, over a total distance of 1561 km. The most common cetacean sighted was the spinner dolphin, Stenella longirostris (~0.238 individuals/km) most frequently in pods of 15-20 individuals, in relatively-shallow to deep waters (82-2310 m). All those spinner dolphins that were positively identified from photographs were of the pelagic form (S. l. longirostris). Other cetaceans sighted were the short-finned pilot whale, Globicephala macrorhynchus, Risso's dolphin, Grampus griseus, the bottlenose dolphin, Tursiops sp., the false killer whale, Pseudorca crassidens and the sperm whale, Physeter macrocephalus. [ABSTRACT FROM AUTHOR]

The first mass stranding of Risso's dolphins Grampus griseus on the Peruvian coast occurred on Pozo de Lizas Beach (17° 42'30.3"S 71° 18'48.7"W), port of Ilo, Department of Moquegua, southern Peru, between 7 and 8 June 2007. At least 14 Risso's dolphins were stranded along 1.5 km of beach. Just 7 of them could be sized and 8 sexed; this group was composed of 7 males and a single female plus a juvenile of undetermined sex. Mean standard body length of the males was 299.67 cm (SD: 9.91 cm, range: 292-317 cm) and the female measured 289 cm. The entire group, including four individuals found alive, was illegally butchered by the local people to use the meat as food, while other remains were used as bait in the pelagic longline fishery. This record fills a distributional gap of about 1000 km in the known distribution of the species between central Peru and northern Chile. Additional education is required for improved conservation strategies in future cetacean strandings. [ABSTRACT FROM AUTHOR]

Hybrid cetaceans have been documented to occur both in the wild and in captivity. Identifying wild hybrid individuals can be problematic in the absence of genetic techniques, but published accounts indicate that intermediate morphological characteristics are often present. Between 2010 and 2013, a land-based and boat-based study of the Risso's dolphin (Grampus griseus) was carried out in nearshore waters around the Eye Peninsula located on north-east Lewis, Scotland. Three atypical individuals were photographed which exhibited morphological features intermediate between Grampus and the common bottlenose dolphin (Tursiops truncatus). These individuals were typically larger in body size than Tursiops, and had a dorsal fin shape and size consistent with Grampus. Two individuals had coloration most similar to Tursiops and the third exhibited extensive white linear scarring consistent with Grampus. The intermediate morphology was most apparent in the head shape, with all three individuals exhibiting a defined (in contrast to Grampus) but very short (compared with Tursiops) rostrum and two having an unusually steep (compared with Tursiops) forehead. On one occasion, one of the atypical individuals was observed within a mixed-species school of Grampus and Tursiops. There were four further sightings of atypical dolphins associated with Tursiops-only schools. Atypical dolphins were not recorded within Grampus-only schools. These observations are consistent with hybridization between free-ranging Risso's and bottlenose dolphins, the first such occurrence to be documented for these species in UK waters. The context and significance of these hybridization events are unknown. [ABSTRACT FROM PUBLISHER]